Hours of Prayer & the Heavens
View Advanced Biblical Year Starting Options (For Advanced Users Only)
Crescent Visibility Map & Day Slider
Click To Read An Explanation of the N S E W Diagram Here
What it is. The little N / E / S / W dial is a compass - a top-down, bird's-eye view of your horizon, as if you were standing in the middle looking down at the directions all around you.
The letters. N, E, S, W are the compass directions: North at the top, East on the right, South at the bottom, West on the left - just like a paper map.
The arrows. The ☼ arrow points to the direction the sun is in the sky at the time set by the day slider; the ☾ arrow does the same for the moon. If the ☼ points right, the sun is in the east at that moment; pointing straight down means due south, and so on.
Bright vs faint. A bright, solid arrow means that body is above the horizon (up, and visible). A faint, dimmed arrow means it is below the horizon (down - nighttime for the sun, or the moon has set).
Watch it move. As you drag the day slider, the time changes and the arrows swing around to follow the sun and moon - roughly east at sunrise, south around midday, west toward sunset (in the northern hemisphere; mirrored in the southern).
Why it sometimes loops and sometimes swings. Over a whole day the sun's arrow makes a full circle when your location is farther from the equator than the sun is for that season, but it swings out and reverses like a pendulum when you are nearer the equator (inside the tropics). Both are correct - it is simply how the sky behaves at different latitudes. The dimmed part of the path is the sun passing below the horizon at night.
Tip. You can also drag the ☼ sun around the dial to scrub the time of day.
Hours of Prayer — 3rd · 6th · 9th
Sun & Twilights
Moon
Next New-Moon Crescent
Eclipses (NASA)
Month View — Elongation at Sunset
🌞 Equinoxes & Solstices — the Equinox & the Biblical New Year
🪐 Orbits — Earth & Moon Positions for the Viewed Day
🌙 Moon Phases, Perigee & Apogee — Viewed Year
✨ Mazzaroth — Sun & Moon Among the Constellations (Job 38:32)
📯 Years & Cycles — Sabbatical (Shemitah) & Jubilee
🌿 Omer Count — Fifty Days to Shavu'ot
🌑 Eclipse Finder — All Eclipses of the Viewed Year
Year Overview — New Moons & Expected Sighting Evenings
Methods, Zones & Resources
Hours of prayer. The daylight from sunrise to sunset is divided into twelve equal parts; the 3rd, 6th, and 9th hours are the ends of the 3rd, 6th, and 9th twelfths (Matthew 20, John 11:9, Acts 3:1).
Crescent thresholds. Two tiers are used (geocentric sun–moon elongation at local sunset, waxing moon): 10.5° – 10.85° — Possible But Uncertain: the crescent could be sighted, watching and witness reports decide; 10.85° and above — Expected Visible In Most Cases, weather and horizon permitting. The "expected" evening highlighted on this page uses the 10.85° standard, but an evening in the uncertain band may prove to be the true first crescent.
Map zones. For every point on the map, the moment of that place's local sunset on the viewed date is computed, then: Zone 1 — elongation ≥ 12.5° with the moon at least 7° high at sunset (easily visible); Zone 2 — elongation ≥ 10.85° with the moon above the horizon (visible in good conditions); Zone 3 — elongation under 10.85°, or the moon is on/below the horizon at sunset (not expected; evenings in the 10.5°–10.85° band are Possible But Uncertain rather than strictly invisible). Because sunset sweeps westward, the zones open toward the west — the same characteristic curves seen on classical crescent-visibility charts. The map backdrop is NASA Blue Marble imagery (public domain), served from this site — if the image is unavailable, simplified outline continents are drawn instead; all zone math is original to this page.
Ancient & future dates. Years are entered with the AD / BC buttons (year 4 with BC selected = 4 BC; supported back to 4500 BC and forward to 9999 AD). Calculations include the ΔT correction for Earth's slowing rotation (about 3 hours by 1 AD), without which ancient moon times are badly wrong. Dates are shown in the standard (proleptic Gregorian) calendar with the Julian-calendar equivalent displayed beside ancient dates; the year-from-creation count follows WYLH reckoning (2026 AD = 5937). Precision gradually decreases for the most ancient dates.
Day/night shading. The slider shades the night side of the flat map at the chosen moment and places ☀ and ☾ where the sun and moon are directly overhead.
Compare & verify (external tools). UKHO Websurf 2.0 crescent visibility indicator ↗ · UKHO Websurf ↗ · USNO sun & moon data for one day ↗ · NASA SKYCAL sky-events calendar ↗ · EliYah new-moon visibility charts ↗ · WYLH Biblical Calendar page ↗